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Post by Deleted on Jan 5, 2018 8:03:48 GMT -8
Even with these commercially purchased clays the vendor warns of minor variations from lot # to lot # even from the same producer. It comes from the fact that clays are laid down in nature over centuries of erosion and the deposits reflect that variation, usually in the amount of trace elements which can affect the finished product. Bricks too and even ceramic fibers are made from natural resources and thus underlie those unavoidable variations as well. |
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Post by peterberg on Jan 5, 2018 8:13:55 GMT -8
Not a single combustion core of whatever construction has been built out of this material to this day, not even by Joseph Davidovits himself. Assurance that some clay has been geopolymerized sounds nice but is not really cutting the cake, sorry.
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Post by Deleted on Jan 5, 2018 9:27:46 GMT -8
Not a single combustion core of whatever construction has been built out of this material to this day, not even by Joseph Davidovits himself. Assurance that some clay has been geopolymerized sounds nice but is not really cutting the cake, sorry. I have build cook stoves from clay soil using geopolymer technology, which to my knowledge are still in use since many years. The few I have build in Germany have been disposed after testing. I assume if I prolong the riser of the newest one and publish pictures or videos of it burning at maximum load, you will still not aknowledge it as it is not used as the core of an RHM. As I have no use for a RHM I will never build one. |
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Post by Jura on Jan 5, 2018 10:45:23 GMT -8
I assume if I prolong the riser of the newest one and publish pictures or videos of it burning at maximum load, you will still not aknowledge it as it is not used as the core of an RHM. As I have no use for a RHM I will never build one. Karl I took your words as quite sharp. My solution is to announce a workshop where someone offering his place would gain an RMH and the geopolimers would have a chance to become tried and tested material, how about such idea? EDIT: I forgot to as if the state of your health would allow you to take up such role ? I may contact ppl in SiebenLinden ecovilage with that regard. The only thing I may offer is my presence and will to give a hand with construction. During my travels to so called "global south" I also encountered ppl who would not be able to afford the cost of materials for construction of a ceramic RMH nor even an efficient cooking stove. So cutting the costs and obtaining construction material locally would lift our stoves onto quite higher level of sustainability. |
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Post by Deleted on Jan 5, 2018 10:49:40 GMT -8
Jura great idea. Sadly my health does not allow me to travel anymore.
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Post by Jura on Jan 5, 2018 10:57:03 GMT -8
Jura great idea. Sadly my health does not allow me to travel anymore. I have just edited my post asking about that issue after I recalled you not being in "brand new modus operandi" . |
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Post by Deleted on Jan 5, 2018 11:16:08 GMT -8
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Post by peterberg on Jan 5, 2018 12:25:58 GMT -8
I assume if I prolong the riser of the newest one and publish pictures or videos of it burning at maximum load, you will still not aknowledge it as it is not used as the core of an RHM. Karl is not entirely correct here, I tend to applaude good experiments and testing. Rambling that goes on and on about the virtues of a certain material without any testing in real life situations on the other hand won't be recieved that well. |
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Post by Deleted on Jan 5, 2018 13:58:11 GMT -8
I assume if I prolong the riser of the newest one and publish pictures or videos of it burning at maximum load, you will still not aknowledge it as it is not used as the core of an RHM. Karl is not entirely correct here, I tend to applaude good experiments and testing. Rambling that goes on and on about the virtues of a certain material without any testing in real life situations on the other hand won't be recieved that well. I will build another one without such extreme insulation, but still able to compete with IFB. With the other I would come to close to the ceiling of my balcony. Will need warmer weather though. Loess loam with zeolite based binder as a worst case sample. |
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Post by briank on Jan 5, 2018 16:54:51 GMT -8
I think in the end the best cheapest and simplest use of geopolymers is going to be as a coating, a simple cheap diy formula so that anyone can build and mortar in place a red brick firebox and riser, them coat them with successvive coats of geopolymers. Cement paving squares could even be used on top of fireboxes and primary bells, but with multiple coats applied so they are harder, insulative, and resistant to heat in general.
Red bricks are cheap (often free) and universally available. If not then adobe bricks are.
Building a rocket core out of red bricks or adobe, then just painting layers of geopolymer over surfaces exposed to fire and extreme heat, makes presses and molds and possibly even oven heating unnecessary.
If such a coating could be developed and perfected, it could then be made available to diy builders.
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Post by Deleted on Jan 5, 2018 17:46:38 GMT -8
If such a coating could be developed and perfected, it could then be made available to diy builders. Try a zeolite based LTGS binder with any alumino silicate. |
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Post by peterberg on Jan 6, 2018 1:27:20 GMT -8
I will build another one without such extreme insulation, but still able to compete with IFB. With the other I would come to close to the ceiling of my balcony. Will need warmer weather though. I am really curious how this will develop, please carry on. |
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Post by Deleted on Jan 6, 2018 12:20:14 GMT -8
Not a single combustion core of whatever construction has been built out of this material to this day, not even by Joseph Davidovits himself. Assurance that some clay has been geopolymerized sounds nice but is not really cutting the cake, sorry. Hi Peter, I made a 180 mm rocket stove heat riser with geopolymer in 2016 when I was deep in the experiment craziness. Two pictures here :   There is a thread somewhere where I talk about it. The thing was clearly insulative but very fragile. It was impossible to unmould a riser less than 180mm in diameter.. way to fragile. It didn't melt out or anything when it was it place. Maybe I wasn't right on some things I tried but nonetheless I went quite far on my geopolymer craziness.. only to stop a few months later to go back to those ceramic insulatives sleeves that work well and that I could use with confidence that I won't have to come back to repare the heater in some years. I'm really looking forward @karl to see more development with these geopolymer insulative materials. Flame contact insulating refractory materials are so damn expensive ! I propose you one thing if you're OK :At my home I have adobe moulds, 0-0.02 mm refractory grog, pure dry lye, abundant clay perfect for brick making and a butane torch. If you give me a step by step recipe to follow, I'll gladly make some bricks of 5x10x20 cm and then see if they can withstand my butane torch or the riser of my cookstove. What do you say? Regards, |
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Post by Jura on Jan 7, 2018 4:18:31 GMT -8
I made a 180 mm rocket stove heat riser with geopolymer in 2016 when I was deep in the experiment craziness. A bit off topic but I have a question: what kind of tube did you use as the internal mould form? I didn't manage to get any pipe of that size and had to wrap a 160 mm sewage pipe with a PVC lining. I missed your thread about the geoplymer heatriser.. but yesterday I kept a piece of flyash geopolymer and it was hard and not breakable in hands. (as it was commercial I could not get the recipe) I'd be happy to follow your experiments. Stovy New Year! |
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Post by Deleted on Jan 7, 2018 7:58:36 GMT -8
Maybe I wasn't right on some things I tried but nonetheless I went quite far on my geopolymer craziness.. With your mixture you have ignored virtually all my recommendations. If you had asked my I would have told you that your mixture is prone to failure and will not give you a satisfying result. Geopolymers are not dependent on weight reduction for low heat conduction. You are welcome. The cheap 0-0.2 mm red chamotte is not a grog as it has less than 19% alumina and a firing temperature of approx. 1140 ° C. Most of the more than 75% of silica content is available as quartz, which results in a relatively high thermal conduction and expansion. 0-0.2 mm is far to coarse for a binder, thus it is only suitable as an aggregate. I have described how to make simple LTGS binders in the two following threads: Simple and Straight away LTGS Binder donkey32.proboards.com/thread/2372/simple-straight-away-ltgs-binderStraight away LTGS Binder based on Reactive Minerals donkey32.proboards.com/thread/2399/straight-binder-based-reactive-mineralsFor the chemical reactions required to make a binder it is very importand to keep the mixture of lye and alumino silicate as concentrated and hot as possible. If your clay is wet then you need to evaluate the water content first to be able to calculate a proper composition based on dry mass. 10% binder, which equals 5% lye will give very strong results with clay. You can add some of your chamotte to save some water and let it dry faster. You may consider to get zeolite. Ebay France www.ebay.fr/itm/ZEOLITH-0-1-MM-25-KG-ZEOLITE-SAND-KLINOPTILOLITH/121152119381?hash=item1c353aa255:g:TF0AAOSwFNZWu142Maybe you can find another resource in France. Zeolite 0-1mm is the cheapest dissolvable for a binder with NaOH. Zeolite powder is much better but significantly more expensive. www.ebay.fr/itm/Zeolith-25-kg-Filtermaterial-Phosphatbinder-Zeolite-Zeolit-Koi-Garten-Teich/120956892701?hash=item1c2997b61d:m:mj2Fgj-8wSJ2jondf1zSu3QThe simplest way to reduce the density is to make an apparent foam by adding microballoons which are available as borosilicate glass or plastic. Borosilicate glass has a density of about 2.2Kg per liter and the microballons just about 0.2Kg, thus more than 90% are air. Just 10% per weight give a much higher volume increase. A mixture of clay and feldspar can be made very liquid and be used to protect cheap rock wool against high heat. |
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